WiMAX is a technology based on the IEEE 802.16 standard, and aimed as providing broadband wireless data access. The WiMAX Network Reference Model specifies network functional entities and reference points that exist between various groups of network functional entities, which are typically implemented through Ethernet Layer-2 networks or IP networks. The Access Service Network represents an aggregation of functional entities and message flows associated with access services. An ASN typically includes, among other things, a plurality of Base Stations (“BS”s) and a plurality of Access Service Network Gateways. An ASG represents an aggregation of Control Plane functional entities and in some cases, Bearer Plane routing or bridging functions. Practically speaking, an ASG acts as a layer-2 traffic aggregation point within an ASN. Reference point R4 consists of Control Plane and Bearer Plane protocols that originate and terminate in functional entities of an ASN that coordinate Mobile Station (“MS”) mobility between ASGs. See, for example, the WiMAX Forum Network Architecture (Stage 2: Architecture Tenets, Reference Model and Reference Points), Release 1.1.1, Sep. 12, 2007, WiMAX Forum, which is hereby incorporated by reference in its entirety.
It is necessary for ASGs to maintain an accurate and up-to-date record of R4 connectivity and routing information for the ASN in order to ensure, among other things, that MS handoff occurs properly. Therefore, changes in the R4 connectivity and routing information should be reflected as quickly as possible in an ASG's databases in order to reduce the chance of MS handoff errors. An ASG typically maintains several databases, including without limitation: an R4 peer database for ASG to ASG associations, a BS database for BS to ASG associations, a Paging Controller and Paging Group database for Paging Controllers and Paging Groups configured on ASGs, an Authenticator database for Authenticators associated with an ASG, and an R4 Tunnel Address database for R4 Tunnel Addresses configured on an ASG.
The current approach to updating an ASG's databases is to configure changes through manual or script-based use of a Configuration Manager. This is similar to approaches used in cellular networks, which also uses Base Stations to provide wireless access to mobile stations, with the Base Stations in turn controlled by some form of Base Station controller or Mobile Switching center. This approach has several problems: it lacks a mechanism for the automatic discovery of newly added ASGs; it is labor-intensive and introduces opportunity for error, since operators must reflect changes in network topology and routing information by manually configuring the databases of every ASG within the ASN; and it is a time-consuming approach which can introduce considerable delay in reflecting changes in network topology and routing information, during which MS handoff errors may occur. While such an approach is not particularly problematic for cellular networks, WiMAX networks can have many more Base stations and ASGs than conventional cellular networks.
It is, therefore, desirable to provide a simplified, cost-effective method for automatically discovering newly added peer ASGs, and updating peer ASGs with R4 connectivity and routing information.